Process evaluation of the Integrated Cardiac Rehabilitation Program Employing Smartphone Technology (I-CREST) for coronary heart disease management

AIMS: To evaluate the Integrated-Cardiac Rehabilitation Employing Smartphone Technology (I-CREST) program's implementation fidelity, impact mechanisms, experiences, and contextual factors influencing its delivery from post-myocardial infarction participants and healthcare professionals. METHODS AND RESULTS: A mixed-methods approach following the Medical Research Council (MRC) guidelines for complex interventions, focusing on implementation, mechanisms of impact, and context. Three quantitative data sources were collected: (ⅰ) records of intervention delivery; (ⅱ) records of intervention delivery time; (ⅲ) content analysis on the frequency of contextual factors from the qualitative interview data. Qualitative data were collected through individual semi-structured interviews with 14 I-CREST participants and healthcare professionals (HCPs). The I-CREST program achieved a high level of intervention delivery fidelity, with an average delivery time of 3.02 h per participant over 6 weeks. Deductive content analysis of participants' experiences found key mechanisms of impact, including knowledge and belief, self-regulation skills and abilities, and social facilitation. Thematic analysis of participants' experiences found four main themes: benefits of the I-CREST intervention; a change in mindset; life beyond the 6-weeks intervention; and the potential of I-CREST. Inductive content analysis of both participants' and HCPs experiences identified implementation-level factors such as recruitment, interoperability and cost, and mechanism/experience-level factors like work commitments and motivation that influenced the I-CREST program's implementation, mechanisms of impact, participants' experiences and trial outcomes. CONCLUSION: The I-CREST program is a promising home-based cardiac telerehabilitation option that was well accepted. However, further revisions are needed if I-CREST is to achieve its full intended benefits and see successful implementation in real-world clinical settings.